Automatic gas cut-off.



G. L. COFFMAN.

AUTOMATIC GAS CUT-OFF.

APPLICATION FILED MAR. 30, I916.

Patented Mar. 20, 1917 2 SHEETSSHEET 1- I I l 21 II I I 'HI l 1 9 l In1.1 9 5;:

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G. L. COFFMAN.

AUTOMATIC GAS CUT-OFF.

APPLICATION FILED MAR. 30. 1916.

1,21 9,627. Patented Mar. 20, 191?.

2 SHEETSSHEET 2.

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GEORGE L. COFFIVEAN, OF OKLAHOMA, OKLAHOMA.

AUTOMATIC GAS CUT-OFF.

7 Specification of Letters Patent.

Patented Mar. 20, 1917.

Application filed March 30, 1916. Serial No. 87,690.

To all whom it may concern:

Be it known that I, Gnonen L. COFFMAN, a citizen of the United States,residing at Oklahoma city, in the county of Oklahoma and State ofOklahoma, have invented certain new and useful Improvements in AutomaticGas Out-Offs, of which the following is a specification, reference beinghad to the accompanying drawings.

The invention pertains to a device for antomatically shutting off thesupply of gas when the pressure becomes too low, an object being toprovide a device of this class extremely sensitive to reductions inpressure and positive and certain in its action.

Other objects and advantages of the invention will be set forth 'in theensuing description.

The drawings show one embodiment of the invention in practical form.

Figure 1 is an elevation view .of the device, showing the position ofthe parts after the pressure of the gas supply has dropped and thesupply has been cut off.

Fig. 2 is a sectional view in the same direction as Fig. 1, but showingthe position of the parts when the gassupply is under normal pressureand is passing through the device.

Like characters of reference designate like parts in both the figures.

The device includes a vertical cylindrical body 5 which is closed at itsupper and lower ends and adapted to support other parts.

A valved inlet port 6 enters one side of the lower end of the body 5,and a pipe 7 leads from said port up the axial center of said body tothe upper end wall 8 thereof; the lower end of the body being alsoprovided with an outlet port 9.

In installing the device for use, the gas supply pipe 10 is connected tothe inlet port 6, and an outlet pipe 11 leads from the port 9 to aburner or other point of consumption, not shown.

In passing through the device, the gas from the pipe 10 is forced up theinner pipe 7; out of said inner pipe 7 through holes 12 in its upper endand into the space 13 surrounding said pipe; and thence out through theoutlet port 9 and pipe 11.

An upward extension 14 is screwthreaded to the body 5 with a gas-tightfit, and the upper end wall of this extension is formed by a flexiblediaphragm 15, a protecting cap 16 being provided for this diaphragm andscrewthreaded to said extension.

One or more small branch tubes 17, permanently open, lead away from thebore of the inner pipe 7 at a point below the holes 12 and upwardthrough the upper wall 8 of the body 5 into the compartment 18 under thediaphragm 15, said tubes 17 pipe 7, and upper wall 8 preferably beingintegral in order to be gas-tight.

The inlet port 6 is provided with a cutoff valve 19, preferably of thesliding-gate type shown, whose stem 20 projects upward and is PlfOVlflQdwith a weight 21 for closing it.

The upper end of this stem 20 passes slidably through a hole 22 in thehorizontal portion 23 of a supporting arm 24 which is secured to theside of the body 5, and this stem is provided with a notch 25 which maybe hooked into engagement with said arm at said hole to hold the valve19 open.

On the side of the stem 20 adjacent the body 5, a small standard 26 ismounted on the arm 24, the upper end of this standard having a T head2!.

This head 27 houses and guides one end of a bar 28 which passes slidablythrough a diametric slot 29 in the stem 20 and through a similar slot 30in a standard 31 mounted on the outer end of the arm 24.

The bar 28 is provided on. one side of the stem 20 with a shoulder andon the other side with a pin 33, so as to have only a vertical slidingmovement on said stem; and the housing 27 contains a spring 341 whichacts on said bar in a direction to cause it to unhook said stem fromengagement with the supporting arm 24: and allow the valve 19 to beclosed by the weight 21.

To hold the stem 20 positively hooked and the valve 19 open, the outerend of the bar 28 is provided with a hook 35 which may be hooked over apin 36 in the outer standard 31.

In further arrangement, a lever 37 is fulcrumed in the upper end of theouter stand ard 31, this lever also passing through the diametric slot29 of the stem 20 as a con-- venient construction for holding associatedparts alined on the same plane.

The outer end of this lever 37 is connected operatively to the outer endof the bar 28 by a link 38, and the inner end of said lever to thecenter of the diaphragm 15 by a rod 39 which passes loosely through thecap 16.

To set the device to allow a flow of gas, the stem 20 is lifted manuallyby its handheld 40 to open the valve 19, and then swung outward inopposition to the spring 34: to have its notch 25 hook onto the arm 2%and hold the valve open.

Then, the gas which is entering the open valve 19 and port (3 sets uppressure under the diaphragm 15 through the tubes 17, the diaphragmraising up the inner end of the lever 37 and causing the outer end ofsaid lever to swing the outer end of the bar 28 down into hookedengagement with the pin 36.

As long as the gas is under sullicient pres sure to support thediaphragm 15 and attached parts, the bar 28 will be held down in hookedengagement with the pin 36 and the spring 34: will thereby be preventedfrom tripping the notch ot' the stem 20 out of engagement with thesupporting arm 24; but when a reduction in gas pressure allows thediaphragm and the inner end of the lever 37 to fall the bar 29 willbe'tripped from engagement with the pin 36 and allow the spring 34L totrip the stem 20, the weight 21 instantly closing the valve 19.

In order to insure suliicient back pressure in the compartment 18 tosupport the diaphragm 15 when a burner or other termination of theoutlet pipe 11 releases too much gas, a small float 11 fits the upperend of the inner pipe 7 as a piston.

When no gas is forced into or through the device, this float 4L1 restson shoulders 42 in the pipe 7.

The gas must raise and support the float 41 in order to pass through theholes 12, and the back pressure thus set up is communicated through thetubes 17 to the diaphragm compartment 18.

For convenience in construction and in assembling the float -11, thepipe 7 opens upward through the upper wall 8 and is closed by aremovable plate 4L8 and gasket 14 which are held to said wall by screws45.

Having thus described the invention, I claim:

1. An automatic gas cut-off, including a closed casing having an inletport and an outlet port, a pipe extension leading from the inlet portand extending into the casing, a lateral outlet hole being provided inthe said pipe extension, a float slidable in the pipe extension andnormally held away from the outlet hole therein by the pressure with inthe casing, a valve in the inlet port of the casing, means for closingthe valve, and means whereby pressure within the casing holds the valveopen.

2. In a device of the class described, an inclosed casing having aninlet port and an outlet port, a pipe extension leading from the inletport upward in the casing and having an outlet hole in its upper end, afloat fitting in th upper end of said pipe extension, a support for thefloat in said pipe extension and below the said outlet hole, a diaphragmcompartment having one of its walls composed of a flexible diaphragm,said compartment being in communication with that portion of the pipeextension below said outlet hole, a valve in the inlet port of thecasing, and means whereby pressure on the diaphragm holds the valveopen.

3. in a device of the class described, a closed casing having an inletport and an outlet port, a pipe extension leading from the inlet portupward in the casing and having an outlet hole in its upper end incomnninieatimi with the outlet port, a float fit ting in the upper endof said pipe extension, a support for the float in the pipe extensionand below said outlet hole, an upward eX- tension screwthreaded to thecasing and forming a diaphragm compartment, a tube leading from the pipeextension at a point below the support of the float and upward throughthe upper wall of the casing into the diaphragm compartment, a diaphragmforming one wall of the diaphragm compartment, a valve in the inlet portof the easing, and means whereby internal pressure on said diaphragmholds said valve open.

4:. An automatic gas cut-ofi including a closed casing having an inletport and an outlet port, a pipe extension leading from the inlet portand projecting into the casin a lateral outlet hole being provided inthe pipe extension, a float slidable within the pipe extension andadapted to close the outlet hole, but normally held away therefrom bythe pressure within the casing, a diaphragm compartment having adiaphragm for one wall thereof, a tube leading from the pipe extensionto the diaphragm compartment, a valve for the inlet port of the casing,and means whereby internal pres sure on said diaphragm holds said valveopen.

5. An automatic gas cut-off, including a closed casing having an inletport and an outlet port, a diaphragm compartment in communication withthe chamber, a diaphragm forming one Wall of the said compartment, avalve for the inlet port of the casing, a slidably mounted stemoperatively connected to the valve and controlling the opening andclosing thereof, said stem having a notch in one side thereof, a guidemember for the stem adapted to be engaged by the notch to hold the valvein an open position, a spring actuated slide for moving the stemlaterally to disengage the notch from the guide member, means forholding the slide in inoperative position, and means actuated by thebefore mentioned diaphragm for releasing the slide when the pressureWithin the casing falls below a predetermined point.

6. In a device of the class described, a closed casing having an inletport and an outlet port, the inlet port having a valve, the valve havinga sliding stem projecting upward for opening and closing it, the casinghaving an arm slidably embracing and guiding the upper end of the stem,the stem having a notch adapted to be hooked into engagement with thearm to hold the valve open, and having a weight to force a movement ofthe valve when the stem is tripped from engagement with the arm, aspringaotuated sliding bar mounted horizontally and arranged to trip thestem from engagement with the arm, a fixed locking stop carried by thearm, the bar having a notch adapted to be engaged With said stop toprevent the bar from tripping the stem, a diaphragm adapted to receivepressure from the casing, and operative connections whereby pressureexerted upon the diaphragm premunication With the casin vents the barfrom being released from said stop.

7. An automatic gas cut-ofl', including a casing having an inlet portand an outlet port, a diaphragm compartment in coma diaphragm formingone Wall of the said compartment, a valve for the inlet port, a slidingstem operatively connected to the valve and controlling the opening andclosing thereof, said stem having a notch in one side thereof, a guidemember adapted to be engaged by the notch to hold the valve in an openposition, a spring actuated trip member for disengaging the notch of thestem from the guide member, and means actuated by the before mentioneddiaphragm for automatically releasing the said spring actuated tripmember when the pressure within the casing falls below a predeterminedpoint.

Witness my hand this day of March,

GEORGE L. COFFMAN.

Copies of this patentmay be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

